The primary objective of this research is to prepare better synthetic oxygen carriers than are now known. Systematic quantitative studies are being carried out on how changes in the ligands and in the metal alter the oxygen carrying ability of metal complexes. An essential part of this investigation deals with the nature of the bonding of the dioxygen moiety in these metal complexes, and the structures of the oxymetal complexes. Also of utmost importance are the reactivities of the coordinated dioxygen in these systems. Research on these various aspects of the problem are in progress for model complexes of cobalt, iron and manganese. BIBLIOGRAPHIC REFERENCES: "Reversible Adsorption of Oxygen on Silica Gel Modified by Imidazole-Attached Iron Tetraphenylporphyrin," J. Amer. Chem. Soc., 97, 5125 (1975), Orlando Leal, David L. Anderson, Robert G. Bowman, Fred Basolo, and Robert L. Burwell, Jr. "Kinetics and Thermodynamics of Oxygen and Carbon Monoxide Binding to Simple Ferrous Porphyrins at Low Temperatures," J. Amer. Chem. Soc., 97, 6707(1975), Charles J. Weschler, David L. Anderson, and Fred Basolo.